Effects of a time-varying magnetic field on actin protein during volume regulation of bovine adrenal chromaffin cells

Abstract

We tested effects of exposure to a switched 1.5 Tesla magnetic field on actin protein during cell volume regulation in hypotonic medium in cultured bovine adrenal chromaffin cells. Cellular G-actin was increased by the exposure or addition of cytochalasin D, and addition of jasplakinolide to 2 hr-exposed cells decreased G-actin and maintained the normal value. Intracellular morphology and distribution of F-actin measured by confocal laser scanning microscope were changed, but jasplakinolide did not recover the changes. The cell volume was increased rapidly after incubation in hyposmotic medium, followed by their gradual decrease. This cell volume was almost restored to their normal level. Exposure to the time-varying magnetic field increased the peak value and delayed the recovery to the normal value. Preincubation of cytochalasin D indicated the same volume changes as 2 hr-exposed cells. Replacement to hyposmotic medium caused transient decrease in cellular F-actin and then the content was increased instantly to the normal value within 30 min in control cells. These data are suggested that exposure to the time-varying magnetic field influence the volume regulation by affecting actin polymerization or depolymerization. [J Physiol Sci. 2008;58 Suppl:S209]